Hydrated aluminium oxide is a chemical compound commonly referred to as alumina trihydrate. It is used for a wide range of applications including as a fire retardant filler, as a raw material for the production of aluminium, and as a polishing abrasive. However, there are several other synonyms for this compound, such as Gibbsite, Bayerite, and Nordstrandite. These different names often refer to specific types of hydrated aluminium oxide, each with unique properties and uses. For example, Bayerite is commonly used in the manufacturing of ceramics and as a catalyst in the petroleum industry, while Gibbsite has been used as an alternative to lanthanum in the production of phosphors.